Laminitis-related lesions and lameness detection in dairy cattle in Finland

During the last few years of structural changes in agriculture, lameness has become to one of the most important farm issues in Finland. An estimated 90% of lameness is due to hoof problems. However, a national recording system for hoof diseases of cows did not exist in Finland prior to 2002, nor have analyses of risks been investigated. The co-operation project Healthy Hooves (HH) between The Finnish Hoof-trimmers' Association, Suomen Rehu and Vetman was established in 2001 to attempt to improve national hoof health. This research part followed the project and was concentrated on the most predominant hoof problems (haemorrhages, sole ulcer (SU) and white line disease (WLD)) in the HH pilot year 2002. The full HH study-dataset for 2003-2004 consisted of 74410 observations on 41087 cows from 1430 farms. In addition to specific lameness-related hoof lesions and their incidences/ prevalences, increasing interest has been directed towards the lameness detection itself. One aim of this study was to develop an automatic lameness detection system operating in a milking robot by force plates and compare it with lameness scoring (LS) and hoof-trimming data. In the final stage, a neural network model was established to detect/identify lame cows. In WLD and SU cases that produced lameness, acute phase proteins were investigated to determine whether an acute phase reaction (APR) was connected to these hoof lesions, and to evaluate the severity of these reactions. The HH project established a national recording system for hoof problems and identified the most important risk factors. According to the results, WLD and SU were important hoof diseases in Finland, which also might cause clear acute phase reaction in cows. The lactational risks of WLD and SU were strongly affected by the number of times a cow's hooves were trimmed during lactation. In addition, the most important risk factors for WLD (in LH herds) and SU were breed (higher risk in Holsteins compared to Ayrshire), farm type (higher risk in LH than in TS) and parity, but neither high levels of milk yield nor feeding type were found to be risk factors. Parity and breed were dependent on each others in TS-model in WLD and the largest cooperative action was seen with older Holstein cows. Hard flooring in cubicles, compared with mats, was clearly a risk factor for both diseases. In addition, a strong effect existed between other hoof lesions and WLD/SU. While carrying out the HH project, I concluded that the effect of feeding on laminitis- related lesions is probably overestimated in Finland. Laminitis-related lesions are multifactorial problems, with breed, parity (including growing heifers) and cow comfort having the greatest impact. However, when already a risk for laminitis exists, inappropriate feeding may further increase the risk.